Imd July Rainfall Forecast June Rainfall Deficit India Monsoon El Nino

While June recorded a 40 per cent rainfall deficit, the India Meteorological Department (IMD) on Tuesday said rainfall in the month of July was also expected to be below normal, less than 94 per cent of the long period average.

The IMD had predicted 92 per cent rainfall for June, but the month brought in just about 60 per cent of normal rains, making it the fifth driest June since 1901 — the year from which rainfall records are available in India. The shortfall in June has put a question mark over the rainfall prediction for the entire monsoon season.

In May, the IMD had said that under the influence of a developing El Nino phase in the Pacific region, the four-month monsoon season starting in June was expected to bring less than normal rainfall. It had said rainfall during this period was likely to be only 90 per cent of the long-period average. The prediction had assessed that the second half of the monsoon, the months of August and September, could be impacted by El Nino, but the first two months would be largely unaffected. The rainfall deficit in June could force the IMD to re-examine its assessment for the season.

On Tuesday, the IMD released its forecast only for the month of July. The updated seasonal forecast is released only at the end of July every year.

According to the IMD’s latest forecast, while July — the rainiest month of the monsoon season which accounts for 32 per cent of the seasonal rainfall – is also predicted to see below-normal rainfall, it could be substantially better than June.

Interestingly, the IMD’s forecast has only mentioned the upper limit of expected rainfall – it has said rainfall in July was expected to be less than 94 per cent. The monthly forecast for July is being made for the first time. Earlier, only the prediction for June was made.

The monsoon made some good progress in the last few days of June. A week ago, the month of June was staring at the prospect of becoming the driest ever. June is normally expected to bring about 165.3 mm of rainfall. The driest June was in 2009, when it received just 87.6 mm rainfall. There were just four years, including 2009, when the month saw below-100 mm rainfall. This year has now become the fifth, ending up with 99.5 mm of rainfall.

The slight improvement in the last few days is expected to continue into July as well, the IMD said. The first week of July is likely to bring fairly widespread rains in most parts of the country, it said.

“Above-normal monthly maximum temperatures are most likely over most parts of the country, except a few isolated areas in west-central India which are likely to experience normal to below-normal maximum temperatures,” it said.

As of now, weak El Nino conditions are prevailing in the Pacific Ocean, but these are likely to strengthen in July. This is expected to impact rainfall, as well as lead to higher temperatures.

As the IMD had predicted, El Nino had a very small role to play in June. The shortfall in rainfall was mainly because of the absence of any low-pressure systems, a weak monsoonal flow, and lack of favourable external systems like the Madden Julien Oscillation (MJO), a moving system of cloud and wind along the equator that often produces bursts of very good rainfall.